1. Field of the Invention
The present invention relates to an oven assembly containing vertically arranged, horizontally conveying endless conveyor belts, and to a device for transferring food articles from upper to lower conveyors while inverting the food articles and reversing their direction.
2. Description of the Background Art
Commercial production of certain baked goods, such as tortilla chips, advantageously utilizes pass-through ovens through which the article to be baked is conveyed in a continuous process. To minimize the amount of floor space occupied by a pass-through oven, the oven can be provided with a vertical array of horizontally operating conveyors, with the food article being sequentially passed from upper to lower conveyors while being baked.
For example, U.S. Pat. No. 4,508,025 to Schultz discloses a tortilla press and oven unit including a plurality of horizontally rotating, vertically arranged conveyor discs between which are located fixed curved slides for inverting tortillas while transferring them to a lower adjacent disc in the oven.
A different type of transfer device is shown in U.S. Pat. No. 4,309,938 to Harmon. The Harmon patent discloses a smoker including curved guides for forming end portions of conveyor belts into arcuate shapes for inverting food pieces while transferring them from upper to lower belts.
U.S. Pat. No. 3,115,084 to Anetsberger et al. discloses belt conveyors in a dough proofer with vertically corrugated guide plates between adjacent, vertically arranged conveyor belts. The guide plates slidingly redirect movement of a dough piece to reverse the direction of the dough piece onto a lower conveyor belt.
U.S. Pat. No. 2,112,309 to Santillan discloses a tortilla grill with adjacent, vertically arranged, horizontal endless conveyor belts traveling in opposite directions. A moving inclined belt is provided for transferring soft tortillas between conveyors in the upper portion of the grill, and a simple inclined slide is provided down the line for conveying grilled tortillas between conveyor belts.
Commercial ovens are available from Electra Foods Machinery (EFM), of Del Monte, Calif., that include vertically arranged, horizontal endless conveyor belts with adjacent belts traveling in opposite directions. Food pieces are transferred from an upper belt to a lower belt by an array of 32 curved hollow fingers that transfer the food articles between the belts while reversing their direction and inverting the articles. When baking tortilla chips, the curved, hollow fingers of the EFM oven have been found to expand unevenly, causing chips to sometimes fold over during transfer. The chips also tend to stick to the transfer device and build up, requiring an oven shut-down to allow cleaning of the device. Because of the intense heat from the oven in the vicinity of the curved fingers, cleaning is difficult and can cause operator injury. The oven is provided with a back heat shield, which must be removed to provide access to the curved fingers of the transfer device. Because the oven back heat shield attaches to the oven frame with bolts, it is difficult to remove and as a consequence, often is left off during oven use to provide access to the curved fingers of the transfer device.
There remains a need in the art for a conveyor transfer device that reduces product sticking and buildup, and provides easy access thereto with a heat shield in place.